On the one hand, the Gulf of Mexico is bebothered and vexed with
crude oil which, being floaty, tends to float.

On the other hand, there are plans to try seeding parts of the
oceans
with iron compounds in order to promote plankton growth as a
means of sequestering carbon.

If, inter alia
sim podium, we combine these two concepts, we
arrive
at a third.

It is possible to create iron salts of aliphatic (oily) molecules (see
link). These compounds have been proposed as oil additives to
reduce soot formation, and they work because they are soluble in
oil.

So.

If we can douse the Gulf of Mexico with enough of these
compounds
(or pump them in to the rising plume of oil), we will kill two birds
with one stone. (OK, bad choice of metaphor.)

The aliphatic iron salts will preferentially dissolve in the oil,
thereby
increasing its density. At some point, it will sink to the sea bed,
where it will do a lot less harm than it does on the surface, and
where it will be less likely to wind up on beaches, pelicans and
TV. The
oil will eventually degrade, with a bit of luck.

As the oil breaks down, it will slowly leach its ironic compounds
back
into the ocean, thereby trickle-feeding local plankton with what
they need (assuming that currents eventually bring the irony water
back towards the surface) and helping to sequester all that CO2.

Win win!

(I had hoped it would be possible to harvest the iron-enriched oil
with a big magnet, but this seems unlikely even by the lax
standards
of the HB.)

I dunno Max.... I could see stronger arguments for not suppressing its tendency to make its way to the surface. Coating the sea bed with this muck seems to me to more damaging long term. I'll ask Greenpeace.

From the article: "An amount of a C6 to C8
monocarboxylic acid at least equivalent to the amount
of magnesium oxide to be reacted is dissolved in the
iron carboxylate solution as the reaction medium. This
acid can be straight or branched chain and, in
particular, is &#945;-branched. Examples of such acids
are 2- ethylbutyric acid, 2,3-dimethylbutyric acid, 2-
methylpentanoic acid, 2-ethylpentanoic acid, and 2-
ethylhexanoic acid, 2-ethylhexanoic acid being
preferred. For best results, the excess of acid should
not be more than 30%, advantageously from about 10 to
30%."

So you see, they are inventing something that can
dissolve in oil, but it does not react with the oil. It
reacts with the aliphatic monocarboxilic acids. Now,
let's go find an enzyme that converts alkanes into
monocarboxilic acids? Something something carboxilase?

//they are inventing something that can dissolve in oil, but
it does not react with the oil.//

Yeah but, like, that's the point. We make the aliphatic
monocarboxylic acids in a big aliphatic monocarboxylic acid
factory. Then we dump then into the oil, and they dissolve
in it, increasing its density. Enzymes schmenzymes.

Oh, I see. Use oil to sink oil. That's the part my head
wasn't comprehending; Why not use the oil already there
as a
reactant in making the heavy stuff whereby it sinks with
some of the non heavy oil and eventually it's all sunk?

I like the approach. My understanding is that something of the sort is already happening: heavy components of the oil form underwater plumes, light components come to the top. Maybe a chemical could dissove the oil in itself more perfectly so it does not stratify.

I think that what is needed now is for Max to order some of these compounds and make a youtube video showing how they cause greasy oil on water to sink. Plus if the video narrator has an english accent, Americans will figure it has to do with the BBC which means it is smart.

Well before you sequester CO2, you might want to read what 31000 scientists just petitioned the UN to quit deluding the world about CO2 and supposed man-made impact on this huge planet more affected by the rising 2011 sunspot and solar flare activity peaking every 11 years...
And please read how the plant life on this planet only contributes to less than 4% of the oxygen as plants USE oxygen and GIVE OFF CO2 to breathe at night when the sunlight quits falling on plants and trees...
Over 96% of your oxygen we breath comes from cosmic bombardment in the upper atmospheric phenoms.

If you can get BP to SINK PROFITS from 10% of their earnings last year, there could have been 20-tankers encircling the floaties and an inverted reservoir trapping oil (high) and pumping out reasonably purer water (low) as for the greatest percentage of recovery...
I believe, based on my already holding 4% rights to an oil/water separator a farmer invented in 1980 for things similar to safety-clean tank fluids immediate high volume separation. It is nothing more than an inverted U-Tube with outlets at appropriate heights to separate oil from water as is possible with varying conditions, as fast as the diameter of the outlets allows.